seq.c

/*   
 *   File: seq.c
 *   Author: Vasileios Trigonakis <vasileios.trigonakis@epfl.ch>
 *   Description: 
 *   seq.c is part of ASCYLIB
 *
 * Copyright (c) 2014 Vasileios Trigonakis <vasileios.trigonakis@epfl.ch>,
 * 	     	      Tudor David <tudor.david@epfl.ch>
 *	      	      Distributed Programming Lab (LPD), EPFL
 *
 * ASCYLIB is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation, version 2
 * of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include "seq.h"

node_t** 
search(node_t** root, skey_t key) 
{
  node_t** node = root;
  while (unlikely(*node != NULL))
    {
      sval_t node_key = (*node)->key;
      if (key < node_key)
	{
	  node = (node_t**) &(*node)->left;
	}
      else if (key > node_key)
	{
	  node = (node_t**) &(*node)->right;
	}
      else
	{
	  break;
	}
    }
  return node;
}


void
seq_delete_node(node_t** node)
{
  node_t* old_node = *node;
  if ((*node)->left == NULL) 
    {
      *node = (node_t*) (*node)->right;
      node_delete(old_node);
    } 
  else if ((*node)->right == NULL) 
    {
      *node = (node_t*) (*node)->left;
      node_delete(old_node);
    } 
  else 
    {
      /* delete node with two children */
      node_t* pred = (node_t*) (*node)->left;
      node_t* pred_pred = *node;
      while(pred->right != NULL)
	{
	  pred_pred=pred;
	  pred = (node_t*) pred->right;
	}

      skey_t tmp = pred->key;
      (*node)->key = tmp;

      if(pred_pred == *node)
	{
	  (*node)->left = pred->left;
	}
      else
	{
	  pred_pred->right = pred->left;
	}

      node_delete(pred);
    }
}


sval_t
seq_delete(intset_t* set, skey_t key)
{
  node_t** node = search(&set->head, key);
  if (*node == NULL)
    {
      return 0;
    }
  
  seq_delete_node(node);

  return 1;
}

sval_t
seq_find(intset_t* set, skey_t key) 
{
  node_t* node = set->head;
  while (unlikely(node != NULL))
    {
      skey_t node_key = (node)->key;
      if (key < node_key)
	{
	  node = (node_t*) node->left;
	}
      else if (key > node_key)
	{
	  node = (node_t*) node->right;
	}
      else
	{
	  break;
	}
    }
  return (node != NULL);
}

int
seq_insert(intset_t* set, skey_t key, sval_t val) 
{
  node_t** node = search(&set->head, key);
  if (*node == NULL) 
    {
      *node = new_node(key, val, 0);
      return 1;
    }

  return 0;
}